Underground coal mining is much more dangerous than open-pit mining, including the disgusting removal of entire mountain tops to access coal seams. Removing one ton of rock can produce half a ton of coal. In the triple boundaries of Davao del Sur, Sarangani and South Cotobato are the Tampakan mines, a statement that experts consider to be the most dangerous on Earth. The main hazard associated with Tampakan is the 2.7 billion tons of waste produced each year.
Also problematic is the possibility of induced seismic activity, which, combined with waste, could be catastrophic. The atmosphere inside an underground mine is limited and confined and, if gases, dust and fumes are not controlled, extracted or diluted to acceptable levels, they can seriously damage or even kill the miners who inhale them.